<Astragalus
A bone in the ankle allowing articulation of the foot on the leg. It plays a fundamental role in the possibilities of movement of the foot relative to the leg. A double pulley, the joint becomes extremely flexible and totally mobile at both ends and greatly facilitates the ability to race. The fact that a fossil of an amphibian mammal, such as Rodhocetus, has this kind of astragalus indicates an ungulate lineage.
<Vertebrate, vertebrates
Vertebrates are a branch of the phylum Chordata. Vertebrates are distinguished from other Chordates by the dilated anterior end of the neural tube in the brain (consisting of 5 vesicles), the presence of a vertebral column, a perforated pharynx with gill slits opening directly to the exterior (at least in the embryo), a closed circulatory system with a ventral aorta differentiated into a contractile heart, sexual reproduction only, the organization of the body into 3 parts (head, trunk and tail), and a typical internal skeleton.
<Rut
Rut is the physiological state of a mammal that drives it to mate. During rut, the female is receptive. It is during the rut that we witness the battles of the males and courtship.
<Placenta
The mammalian placenta is an embryonic annex that results from the association of fetal chorionic villi with the maternal endometrium. It is an organ of exchange between mother and fetus.
<Keratin, keratinized
Keratin is a fibrillar protein that causes the death of cells it saturates; it thus forms a corneal layer made up of dead keratinized cells. This corneal layer is impermeable and therefore limits water loss at the tegument.
<Amnion, amniotic
The amnion is an ectodermal sac formed around the embryo, defining an amniotic cavity filled with amniotic fluid that protects the embryo against dehydration.
<Endotherm, endotherms, endothermy
An endotherm is an animal whose body temperature remains constant and high, even if the environmental temperature varies. 
<Ectotherm, ectotherms, ectothermy
An ectotherm is an animal whose body temperature varies according to the temperature of its environment.
<Choana, choanae
Choanae are internal nostrils. Olfactory pits (external nostrils) open ventrally and enter into communication with the oral cavity through the choanae. Air is inhaled at the external nostrils, which have a double role: olfaction and breathing.
<Copepods
Copepods are very small crustaceans and are very abundant members of plankton.
<Krill
Krill is a school of microscopic crustaceans.
<Incubation
Incubation is the period during which the embryo develops inside the egg envelopes.
<Gestation
Gestation is the period during which the embryo, then the fetus, develops in the uterus of the female.
<Spermatophore
The spermatophore is a organ containing spermatozoa, which the male can release for the female.
<Metamorphosis
Metamorphosis is all of the processes occurring during post-embryonic development, which result in the changing from one organization and functioning plan to another. Metamorphosis allows the passage from larval to adult stage.
<Glass eel / Elver
Young eels, name given to it when it is at a developmental stage when it goes upstream 
<Milt
Fish sperm.
<Vitellus
Vitellus refers to all the substances contained in the yolk sac.
<Cephalopod, cephalopods
A cephalopod is a marine mollusc with a head bearing tentacles with suckers and which moves by jet propulsion of water through a siphon (example: cuttlefish, squid, octopus, etc.)
<Allantois
The allantois is an embryonic annex formed from a diverticulum of the intestine; it forms with the chorion, the chorion-allantoic membrane, which is richly vascularized and which is the outermost envelope, positioned directly against the shell membranes. It mainly allows respiration of the embryo through the shell.
<Echolocation
Echolocation is a special method of orientation for some animals and is based on the principle of the echo.
<Plankton
All microscopic living organisms (animal or vegetal) suspended in the sea or in freshwater.
< Chiridium Member
The limb is a member that ends with fingers.
< Basal Piece
This is a piece of bone for articulation with the limb girdle.
<Microphagous
Describes an animal that feeds on microscopic living things (including plankton).
<Zoophagous
Describes an animal that only eats foods of animal origin.
<Phytophagous
Describes an animal that only eats foods of plant origin.
<Omnivore
Describes an animal that eats foods both of plant origin and of animal origin.
<Oviparous
Describes an animal that reproduces by laying eggs.
<Viviparous
Describes an animal that reproduces by giving birth to larvae or young (thus giving birth).
<Ovoviviparous
Describes an animal that reproduces by producing eggs that are not laid, but that develop in the genital tract of the female.
<Mucus
Viscous secretion produced by certain mucous membranes (eg it is the mucus produced by the skin of fish that makes them so slimy and slippery).
<Epidermal structures
Cutaneous structures formed from the production of skin cells; hair, feathers, and reptile scales are structures of epidermal origin.
<Dermal structures
Cutaneous structures formed from the production of cells in the dermis; fish scales are dermal structures.
<Jaw
The jaw is formed of two hinged parts: the upper jaw and lower jaw or mandible. It is the jaws that bear teeth.
<Mandible
The mandible is the lower jaw.
< Mandibular fenestra
This is a lateral perforation of the mandible
<Gregarious
Describes a species whose members live in groups
<Embryonic annexes
These are temporary structures, located outside the body of the embryo, which are not involved in the formation of its organs, but in its protection and nutrition. They are discarded at birth or slowly resorbed.
<Cutaneous structures
Cutaneous structures are the elements that cover the skin of animals (hair, scales, etc.)
<Locomotor organ
The organ that allows the movement of the animal (fins, legs etc.)
<Amphibious
Describes an animal that shares its life between aquatic and terrestrial environments
<Rhinarium
The rhinarium corresponds to the nose, i.e. a wet snout with whiskers
<Nose
The nose, as opposed to the rhinarium, is dry, has hair and does not have rows of vibrissae
<Segmented abdomen
<Amnion
<Arborescent
<Cephalothorax
Anterior part of the spiders body including the head and thorax where the legs are attached.
<Scavenger
<Chelicera
Mouth hooks can be poisonous.
<Chlorophyll
This green pigment of chlorophyllian plants absorbs light and allows photosynthesis. There are several kinds of chlorophyll, named a, b, c or d.
<Chloroplasts
<Choanae
<Chromatography
<Cuticle
Impermeable layer covering the epidermis of plants. In animals, the cuticle is a sort of shell surrounding the body of the animal.
<Ecrevisse
<Crayfish
<Elytra
Rigid forewings covering the flexible hind wings.
<Espce_tapissante
< Tapissante species
<Foreshore
Stretch of coastline located between the high seas and low tides.
<Mandibular fenestra
<Deciduous leaves/ evergreen
<Red ant
<Spawn
<Gamete
Male or female reproductive cell
<Royal jelly
Secreted by nurse bees to feed young worker larvae and adult queens and is the only food of queen larvae.
<Pollen grain 
Male reproductive element of conifers, flowering plants and ginkgo allowing the formation of male gametes
<Grasses
<Herbaceous
<Hydrophobic
<Rotproof
<Infralittoral
This area at the bottom of the foreshore is almost always submerged.
<Vermiform larva
<Foliar limb
<Lugols solution
This reagent stains starch and its derivatives in blue-black.
<Opiliones
<Ovule
Female reproductive organs of conifers, flowering plants and ginkgo allowing the formation of the female gamete. The fertilized ovule is the seed.
<Swimming paddle
<Pedipalp
Maxillipeds allowing one to catch and hold food.
<Phycoerythrin
This pigment is found in red algae.
<Pigment
Substance responsible for the color of a plant.
< Silica plant 
<Plasmodesma
Very thin channel, which passes through the cell wall; two adjacent cells can be connected by plasmodesmata.
<Twig
<Rostrum
< Snail sole
<Sporangium
Organ containing spores
<Spore
Cell that allows the propagation of mosses, ferns and fungi and that by germinating allows their sustainability.
<External skeleton
<Stoma
A microscopic pore, typically located on the underside of leaves, which allows gas exchange between the plant and the atmosphere.
<Supralittoral zone
This zone is located at the top of the foreshore.
<Tarsus
<Tentacle
<Thorax
<Bog
<Turret
<Cervical vertebrae